Why is skin cancer not a selective pressure?
Skin cancer has usually been rejected as the most likely selective pressure for the development of black skin because of a belief that it is only rarely fatal at ages young enough to affect reproduction.
Was skin cancer a selective force for black pigmentation in early hominin evolution?
Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.
Why is skin cancer more common in lighter skin tones?
Skin cancer is more common in fair skinned people because they have less of the protective pigment called melanin. People with darker skin are less likely to get skin cancer.
Which subpopulation is at the greatest risk for vitamin D deficiency?
The subpopulation at the greatest risk for vitamin D deficiency is non-Hispanic black females. The subpopulation at the least risk for vitamin D deficiency is non-Hispanic white males.
Who would you expect to be most at risk for developing the bone disease rickets?
Rickets is most common in children who are between 6 and 36 months old. Children are at the highest risk of rickets because they’re still growing. Children might not get enough vitamin D if they live in a region with little sunlight, follow a vegetarian diet, or don’t drink milk products.
What is the selective pressure for darker skin color for lighter skin color?
6. Indigenous populations in low-UV environments tend to have lighter skin tones. One hypothesis is that, in low-UV environments, the selective pressure for dark skin is low. Instead, there is selective pressure for lighter skin, which absorbs more UV radiation, since UV is needed for vitamin D production.
Does folic acid cause skin pigmentation?
Deficiency of vitamin B-9 (folic acid) and B-12 (cobalamin) can cause pigmentation problems leading to patchy skin. Deficiencies of vitamins that occurs due to reduced intake of vegetables and fresh fruits can therefore make you skin appear dull and dark.
Why did the different skin colors evolve?
Theory held that darker skin had evolved in order to afford early humans—who had recently lost the cover of fur—a protection against skin cancer under the tropical sun. But skin cancers, Jablonski knew, almost always arise later in life, when an individual is past reproductive age.
What is the color that represents skin cancer?
Colors and Months for Cancer-Related Ribbons
|Skin cancer (squamous cell carcinoma)||Red and white||May|
|Small intestine cancer||periwinkle blue|
What are the 4 signs of skin cancer?
Redness or new swelling beyond the border of a mole. Color that spreads from the border of a spot into surrounding skin. Itching, pain, or tenderness in an area that doesn’t go away or goes away then comes back. Changes in the surface of a mole: oozing, scaliness, bleeding, or the appearance of a lump or bump.
Does skin cancer have black dots?
Of all skin cancer-related deaths, 79% are from melanoma. In this disease, cancer develops in cells (melanocytes) that produce skin pigmentation. A black or brown spot appears, typically, on the torso of males and lower legs of females.
At what age does skin cancer typically occur?
Age. Most basal cell and squamous cell carcinomas typically appear after age 50. However, in recent years, the number of skin cancers in people age 65 and older has increased dramatically. This may be due to better screening and patient tracking efforts in skin cancer.
Which skin color is most likely to get skin cancer?
People with light skin are much more likely to have their skin damaged by UV rays (and to get skin cancer), but darker-skinned people, including people of any ethnicity, can also be affected. For some people, the skin tans when it absorbs UV rays.
Who is at higher risk of skin cancer?
People who live in areas with bright, year-round sunlight, or those who spend a lot of time outdoors without protective clothing or sunscreen, are at greater risk. Early exposure, particularly for people who had frequent sunburns as a child, also increases skin cancer risks.